U.S. patent application number 12/737420 was filed with the patent office on 2011-07-14 for steam circuit process device and method for controlling the same.
Invention is credited to Christian Bausch, Jurgen Berger, Michael Bucher.
Application Number | 20110167823 12/737420 |
Document ID | / |
Family ID | 41570649 |
Filed Date | 2011-07-14 |
United States Patent
Application |
20110167823 |
Kind Code |
A1 |
Berger; Jurgen ; et
al. |
July 14, 2011 |
STEAM CIRCUIT PROCESS DEVICE AND METHOD FOR CONTROLLING THE
SAME
Abstract
The invention relates to a steam circuit process device,
comprising a reservoir for a liquid working medium; an evaporator
in which the working medium is evaporated by heat supply, the
vaporous working medium being fed to an expander for expansion and
for carrying out mechanical work and being subsequently liquefied
in a capacitor which communicates with the reservoir; a working
medium pump for supplying working medium from the reservoir to the
evaporator. The invention is characterized in that liquid working
medium is supplied in the direction of flow of the working medium
upstream or in the region of the capacitor to the working medium
exiting the expander.
Inventors: |
Berger; Jurgen; (Gerstetten,
DE) ; Bucher; Michael; (Berlin, DE) ; Bausch;
Christian; (Bubesheim, DE) |
Family ID: |
41570649 |
Appl. No.: |
12/737420 |
Filed: |
July 17, 2009 |
PCT Filed: |
July 17, 2009 |
PCT NO: |
PCT/EP2009/005194 |
371 Date: |
March 24, 2011 |
Current U.S.
Class: |
60/645 ;
60/670 |
Current CPC
Class: |
F01K 23/065 20130101;
F01K 9/003 20130101; F01K 15/02 20130101; F01K 9/04 20130101 |
Class at
Publication: |
60/645 ;
60/670 |
International
Class: |
F01K 13/00 20060101
F01K013/00; F01K 21/00 20060101 F01K021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 25, 2008 |
DE |
10 2008 034 977.1 |
Claims
1-13. (canceled)
14. A steam circuit process device, comprising: a reservoir for a
liquid working medium; a vaporizer, in which the working medium is
vaporized by supplying heat, the vaporized working medium being
supplied to an expander to expand and perform mechanical work and
subsequently being liquefied in a condenser, which is connected to
the reservoir; a working medium pump for supplying working medium
from the reservoir to the vaporizer; characterized in that liquid
working medium is supplied to the working medium exiting from the
expander before or in the area of the condenser in the working
medium flow direction.
15. The steam circuit process device according to claim 14,
characterized in that a bypass line is provided for the supply of
the liquid working medium, which produces a connection between the
output side of the working medium pump and the intake side of the
condenser.
16. The steam circuit process device according to claim 15,
characterized in that one end of the bypass line opens into a line
between expander and condenser.
17. The steam circuit process device according to claim 15,
characterized in that one end of the bypass line opens into the
condenser.
18. The steam circuit process device according to claim 15,
characterized in that one end of the bypass line opens into the
expander.
19. The steam circuit process device according to claim 15,
characterized in that a valve is situated in the bypass line, using
which, by changing the working medium volume flow through the
bypass line, the pressure and/or volume flow of the working medium,
which is not branched off through the bypass line, to the vaporizer
can be regulated or controlled.
20. The steam circuit process device according to claim 19,
characterized in that a regulating/control unit is provided, using
which the opening cross-section of the valve is adjustable in such
a manner that the volume flow curve and/or the pressure curve in
the supply line to the vaporizer follows a predetermined target
curve, which results from the power demand at the expander.
21. The steam circuit process device according to claim 19,
characterized in that at least one pressure, volume, mass flow,
and/or temperature sensor is provided, which records the
corresponding variable of the working medium leaving the vaporizer
and transmits it via at least one line to the regulating/control
unit, so that the volume flow curve and/or the pressure curve in
the supply line to the vaporizer is adjustable as a function of the
temperature of the working medium leaving the vaporizer.
22. The steam circuit process device according to claim 20,
characterized in that at least one pressure, volume, mass flow,
and/or temperature sensor is provided, which records the
corresponding variable of the working medium leaving the vaporizer
and transmits it via at least one line to the regulating/control
unit, so that the volume flow curve and/or the pressure curve in
the supply line to the vaporizer is adjustable as a function of the
temperature of the working medium leaving the vaporizer.
23. A method for controlling a steam circuit process device
according to claim 14, characterized in that the working medium
volume flow delivered by the working medium pump varies
independently of a target value for the pressure and/or the volume
flow of the working medium to the vaporizer, and the working medium
volume flow supplied to the vaporizer and/or expander is regulated
and/or controlled in that a part of the working medium volume flow
from the working medium pump is supplied to the working medium
exiting from the expander.
24. The method according to claim 20, characterized in that the
liquid working medium as atomized before or during the supply to
the working medium exiting from the expander.
25. The method according to claim 20, characterized in that, at the
point of the combination of liquid working medium and working
medium leaving the expander, the inner side of the line, which
guides the working medium from the expander, is wetted using liquid
working medium.
26. The method according to claim 23, characterized in that the
amount of the part of the working medium volume flow from the
working medium pump which is supplied to the working medium exiting
from the expander is adjusted as a function of the temperature of
the working medium exiting from the vaporizer.
27. The method according to claim 24, characterized in that the
amount of the part of the working medium volume flow from the
working medium pump which is supplied to the working medium exiting
from the expander is adjusted as a function of the temperature of
the working medium exiting from the vaporizer.
28. The method according to claim 25, characterized in that the
amount of the part of the working medium volume flow from the
working medium pump which is supplied to the working medium exiting
from the expander is adjusted as a function of the temperature of
the working medium exiting from the vaporizer.
29. A drive unit for a vehicle, comprising: a steam circuit process
device according to claim 14; an internal combustion engine whose
exhaust gases are supplied to the vaporizer for heating and/or
vaporizing the working medium; characterized in that the internal
combustion engine at least indirectly drives the working medium
pump.
30. A drive unit for a vehicle, comprising: a steam circuit process
device according to claim 15; an internal combustion engine whose
exhaust gases are supplied to the vaporizer for heating and/or
vaporizing the working medium; characterized in that the internal
combustion engine at least indirectly drives the working medium
pump.
31. A drive unit for a vehicle, comprising: a steam circuit process
device according to claim 16; an internal combustion engine whose
exhaust gases are supplied to the vaporizer for heating and/or
vaporizing the working medium; characterized in that the internal
combustion engine at least indirectly drives the working medium
pump.
32. A drive unit for a vehicle, comprising: a steam circuit process
device according to claim 17; an internal combustion engine whose
exhaust gases are supplied to the vaporizer for heating and/or
vaporizing the working medium; characterized in that the internal
combustion engine at least indirectly drives the working medium
pump.
33. A drive unit for a vehicle, comprising: a steam circuit process
device according to claim 18; an internal combustion engine whose
exhaust gases are supplied to the vaporizer for heating and/or
vaporizing the working medium; characterized in that the internal
combustion engine at least indirectly drives the working medium
pump.
Description
[0001] The invention relates to a steam circuit process device and
a method for controlling the same, the steam circuit process device
particularly forming a part of a vehicle drive or an auxiliary
transmission drive in a vehicle.
[0002] Steam circuit processes, for example, a Clausius-Rankine
process, for generating mechanical power from a heat flow are known
and may be driven, for example, by a separate burner unit in a
power-heat coupling apparatus. For vehicles, steam circuit process
devices are preferably used to exploit waste heat of an internal
combustion engine, the coolant water flow of the internal
combustion engine or preferably its exhaust gas flow being used as
the heat sources, depending on the selection of the working medium
and the temperature control of the steam circuit process.
[0003] CH 171813 describes a steam power plant having a steam
circuit, in which the following components are situated one behind
another viewed in the flow direction of the working medium: a feed
pump, a vaporizer, a superheater, a steam turbine, a condenser, and
a working medium container. A shutoff valve is situated in the flow
direction before the steam turbine, using which the inflow of
vaporized working medium to the steam turbine can be completely
interrupted. A first bypass for branching off a partial flow of
liquid working medium is provided downstream from the feed pump.
Furthermore, a second bypass is provided, using which the vaporized
working medium can be conducted past the steam turbine. Both
bypasses are connectable to one another to conduct flow via
corresponding control valves. The second bypass is always opened
when the shutoff valve in the supply line to the steam turbine is
closed and the steam turbine is to be stopped, or if pressure
spikes in the steam circuit occur as a result of the closing of the
shutoff valve. Since the vaporized working medium would rest in the
supply line in case of closing of the shutoff valve, the
superheater would be destroyed because of the continually rising
introduction of heat--since the heat energy for superheating the
steam is not transferred to the flowing working medium and
dissipated thereby. For this reason, upon closing of the shutoff
valve, the control valves in the first and second bypasses are
switched in such a manner that the vaporized working medium remains
in movement (flows) and is conducted around the steam turbine.
Simultaneously, in this case, liquid working medium is supplied
from the first bypass downstream from the feed pump to the
vaporized working medium, which is conducted past the steam
turbine, for cooling in the connection line of both bypasses by
opening corresponding control valves. The vaporized working medium
which is conducted past collapses in the connection line in this
case and is subsequently supplied via the second bypass to the
condenser for further withdrawal of heat. The two bypasses
therefore only represent a safety apparatus to prevent the
destruction of the superheater and are further used to reduce
pressure spikes in the circuit as a result of the closing of the
valve in the fresh steam supply line to the expander. Power
regulation of the expander is expressly not provided by this
configuration.
[0004] For power control of steam circuit processes, a regulation
of the volume flow of the working medium to the vaporizer is
proposed by DE 102 29 250 A1. This presumes a working medium pump
having variable delivery volume, in order to set a predefined
volume flow value and/or pressure target value for the working
medium in the supply line to the vaporizer. To implement this
specification, a variable-speed drive can be assigned to the
working medium pump, which makes an electric motor necessary for an
electrically operated pump, but is disadvantageous for a vehicle
drive because of the installation space required. Furthermore, it
represents an additional electrical consumer. If the steam circuit
process device is part of a vehicle drive having an internal
combustion engine, alternatively, the working medium pump can be
driven at variable speed by the internal combustion engine using a
control clutch. However, this solution also has a complex design,
is unfavorable with respect to the efficiency, and requires
installation space for the additional control clutch.
[0005] Further controllers for the volume flow of the working
medium in the supply line to the vaporizer are known from U.S. Pat.
No. 4,573,323 and U.S. Pat. No. 4,020,637. A configuration of
multiple pumps is disclosed in the first-mentioned publication,
which take working medium from a reservoir or from an intermediate
container, which is situated between a vaporizer and a superheater
for the vapor phase of the working medium. One of these pumps is
implemented as a controllable injector pump, which is mounted
upstream from a pump driven at constant speed, whose delivery
volume is a function of the intake-side to output-side pressure
differential. Depending on the setting of the injector pump,
working medium is either supplied from the intermediate container
or the reservoir to the subsequent pump. It is not possible using
this device, which is provided in particular for starting
operation, to precisely adapt the volume flow of the working medium
to the vaporizer in the meaning of a power regulation for the steam
circuit process.
[0006] A steam circuit process device which is driven by a burner
unit is known from above-mentioned U.S. Pat. No. 4,020,637. A part
of the mechanical power generated at the expander is used to drive
pumps for the working medium to the vaporizer and for the fuel
supply to the burner unit. Through these measures, equilibrium
exists in normal operation between the power delivery at the
expander and the steam supply required for this purpose, which is
in turn a function of the pressure in the working medium line and
the burner temperature. If a disturbance of this equilibrium
occurs, valves in bypass lines at the pumps are opened, which allow
a recirculation of the working medium and/or the fuel to the pump
intake side. The valves in the bypass lines function as directional
control valves, i.e., as switches which may assume an on state and
an off state. Furthermore, throttle points are provided in the
bypass lines, in order to maintain the pressure gradient at the
pump. Because of the design of the disclosed bypass lines, in case
of opening of the bypass line, only a pressure spike is dissipated,
so that the disclosed device does not allow regulation of the
volume flow and/or the pressure of the working medium in the supply
line to the vaporizer along a target curve, instead the
above-described measures are only taken in case of overpressure.
This is correspondingly true for the pump apparatus in the supply
line to the burner.
[0007] Published application DE 195 24 171 A1 describes a
low-temperature motor (low-temperature engine) for driving work
machines using a gas as the working medium. Liquid gas is conveyed
using a pump and supplied to a vaporizer. The vaporized gas
performs work in a expansion machine and is subsequently cooled and
liquefied in a relaxation element (condenser). The liquefied
working medium is then supplied to a liquid collector (tank) and
conveyed therefrom back via the pump. Furthermore, a bypass is
provided, which branches off a part of the liquid working medium
after the pump viewed in the flow direction of the working medium,
and supplies it to the already relaxed, cooled, and therefore
liquid working medium, which flows out of the condenser. A part of
the working medium flowing out of the pump is therefore supplied
directly to the liquid collector.
[0008] Alternatively, the working medium pump can be driven in a
rotationally-fixed manner by the internal combustion engine. In
such a drive, the working medium pump revolves as a function of the
internal combustion engine speed, so that the delivered working
medium volume flow is proportional to the speed of the internal
combustion engine. In order to obtain a sufficiently high working
medium volume flow to feed the vaporizer or the expander even at
low to moderate engine speeds, larger-dimensioned pumps are
correspondingly used. However, this also means that because of the
rotationally-fixed coupling, a correspondingly higher working
medium volume flow to the vaporizer is also generated at maximum
speeds of the engine. The working medium volume flow conveyed by
the working medium pump is therefore significantly greater than the
required volume flow for the vaporizer or the expander.
[0009] Since the delivery volume flow is therefore always
proportional to the engine speed and not to the occurring quantity
of heat, optimal control of the steam parameters is not possible
using this system. The quantity of heat to be dissipated by the
condenser increases in relation to the useful power of the steam
process due to the non-optimal process control. This is
particularly disadvantageous if the steam circuit device is used in
a motor vehicle, since the installation space available therein is
limited and larger and heavier components result in higher fuel
consumption.
[0010] The invention is based on the object of specifying a steam
circuit process device and a method for controlling the same, which
allow the condenser to be implemented as smaller and lighter than
heretofore, in particular for applications in a motor vehicle or
the drivetrain thereof. Preferably, a separate, variable-speed
adjustable drive machine for the working medium pump is to be able
to be dispensed with simultaneously and nonetheless the delivery
volume of the working medium supplied to the vaporizer or expander
is to be made variable for the purpose of power adaptation, or the
pressure of the working medium in the supply line to the vaporizer
is to be able to be adjusted in accordance with a target
specification. A solution which is simple to design and manufacture
is sought, which occupies a small installation space and
additionally operates energy-efficiently.
[0011] The object according to the invention is achieved by a steam
circuit process device and a method according to the independent
claims. The dependent claims represent preferred embodiments of the
invention.
[0012] The inventors have recognized that by branching off at least
a part of the working medium volume flow upstream from the working
medium pump and supplying the branched-off part to working medium
leaving the expander downstream, the heat dissipation surface can
be reduced and the condenser can be implemented having a smaller
construction.
[0013] A steam circuit process device according to the invention
comprises a reservoir for a liquid working medium and a vaporizer,
in which the working medium is vaporized by heat supply, the
vaporized working medium being supplied to an expander for
expansion and performance of mechanical work and subsequently being
liquefied in a condenser, which is connected to the reservoir.
According to the invention, a working medium pump is provided for
the supply of working medium from the reservoir to the vaporizer.
Liquid working medium is supplied to the working medium exiting
from the expander before or in the area of the condenser in the
working medium flow direction.
[0014] Although the invention can be used particularly
advantageously in motor vehicles, in particular rail vehicles,
trucks, or passenger automobiles, it is also conceivable to use the
steam circuit process device according to the invention or the
control method according to the invention in other mobile
apparatuses or stationary plants, in particular for exhaust gas
energy reclamation in industrial plants. For example, the expander
could be used to drive aggregates.
[0015] A bypass line is particularly advantageously provided for
the supply of the liquid working medium, which produces a
connection between an output side of the working medium pump and an
intake side of the condenser. The bypass line can open directly
into the pressure chamber of the working medium pump, for example,
i.e., it can be situated inside the working medium pump or in a
connection line to the vaporizer. The other end of the bypass line
can also open directly into the condenser or into a line before the
condenser in the working medium flow direction.
[0016] A further preferred embodiment provides that the end of the
bypass line opens into a line between expander and condenser. Such
a mouth can be implemented, for example, as a T-shaped connection
pipe. However, other shapes are also conceivable.
[0017] Furthermore, an embodiment is preferred in which one end of
the bypass line opens directly into the expander. The mouth can be
provided in the outlet area, for example, i.e., downstream from the
expansion chamber of the expander, so that the supply of liquid
working medium which is conducted past the vaporizer occurs in the
expander housing.
[0018] According to the above embodiments, the working medium which
is supplied via the bypass line to the exit of the expander or the
entry of the condenser is essentially provided in a (single) phase,
namely the liquid phase. A single phase means that it is assumed
that the state variables of the working medium cannot suddenly
change, as is the case with cavities, for example. The mixing of
the liquid phase of the working medium branched off via the bypass
line with the vaporized phase of the exhaust steam of the expander
first occurs in the line which conducts the exhaust steam of the
expander or in the condenser.
[0019] The supply of liquid working medium branched off from the
vaporizer to the working medium leaving the expander, which is
typically completely vaporized, has the advantage that the steam is
condensed or at least partially liquefied. Due to the collapse of
the steam at the point of the supply of the liquid working medium,
improved heat transfer and reduced volume of the working medium
flowing from the expander into the condenser results, so that the
heat transfer surface for dissipating the waste heat in the
condenser can be implemented as smaller. Therefore, without
supplying liquid working medium, at least the same quantity of heat
as in typical larger condensers can be dissipated in the condenser
in spite of smaller dimensioning.
[0020] The liquid surface of the liquid working medium is
particularly advantageously enlarged in the area of the supply of
the liquid working medium to working medium leaving the expander.
An enlargement of the liquid surface can be performed by atomizing
the branched-off liquid working medium, for example. For this
purpose, for example, air can be supplied to the liquid working
medium like an aerosol, so that a spray mist results. Such an
atomization can be performed using a Venturi nozzle, for example.
The liquid working medium can also be converted into a type of
spray jet by a suitable nozzle solely using high pressure. The
advantage of atomization is also that the working medium leaving
the expander is mixed better with the supplied liquid working
medium.
[0021] It is also conceivable to wet the pipe which guides the
steam on the inner side using liquid working medium in the area of
the combination of liquid and vaporized working medium.
[0022] A controllable valve can be provided in the bypass line,
using which the pressure and/or volume flow of the working medium
is (indirectly) regulated/controlled in the supply line to the
vaporizer. The working medium quantity, i.e., the volume flow of
the (liquid) working medium flowing into the vaporizer, is thus
varied as a function of the temperature of the (vaporized) working
medium leaving the vaporizer, in that a specific partial volume
flow of liquid working medium is branched off using the bypass and
conducted past the vaporizer, and supplied to the exit of the
expander or the entry of the condenser. The branched-off volume
flow can be adjusted, for example, by changing the opening
cross-section of the controllable valve. In other words, the
opening cross-section of the valve in the bypass line is varied as
a function of the temperature of the working medium leaving the
vaporizer to vaporize more or less liquid working medium. A supply
flow control, i.e., an indirect adjustment of the pressure or
volume flow of the vaporized working medium as a function of the
liquid working medium, is thus achieved.
[0023] Corresponding sensors can be provided for this purpose,
which record the (current) variables of the working medium
(pressure, temperature, conveyed volume or mass flow or volume or
mass flow branched off via the bypass line) of the working medium
in the flow direction of the working medium before and/or after the
vaporizer or before the expander, and transmit them for analysis
via suitable lines to a corresponding regulating/control unit. Of
course, these sensors may be introduced into the vaporizer,
expander, or the corresponding connection lines to the vaporizer or
expander themselves.
[0024] Using the regulating/control unit, the pressure and/or
volume flow of the vaporized working medium generated in the
vaporizer to the expander can be adjusted and/or varied as a
function of the power demand at the expander. The volume flow
and/or the pressure curve of the working medium in the supply line
to the vaporizer (and therefore the volume flow and/or pressure
curve of the vaporized working medium to the expander) can follow a
predetermined target curve, which can be adjusted via the
regulating/control unit. In this way, the waste heat utilization of
the internal combustion engine can be used optimally for every
operating point of the internal combustion engine. For example, in
an operating point of the internal combustion engine in which a
relatively large amount of heat occurs (high engine load, high
engine speed), the liquid working medium volume flow which is
branched off via the bypass can be supplied to the working medium
(steam) exiting from the expander, whereby the steam collapses and
liquefies.
[0025] Such a regulation/control can preferably always be
performed, i.e., during the operation of the internal combustion
engine, and particularly when a relatively large amount of waste
heat occurs.
[0026] In a method according to the invention for controlling a
steam circuit process device, the working medium volume flow
delivered by the working medium pump varies independently of a
target value for the pressure and/or the volume flow of the working
medium to the vaporizer, and thus regulates and/or controls the
working medium volume flow supplied to the vaporizer and/or
expander in such a way that a part of the working medium volume
flow from the working medium pump is supplied to the working medium
exiting from the expander and therefore does not reach the
vaporizer.
[0027] Preferably, the amount of the part of the working medium
volume flow (partial volume flow) from the working medium pump to
which the working medium exiting from the expander is supplied can
be adjusted as a function of the temperature of the working medium
exiting from the vaporizer. This means that the level of the
partial volume flow can be adjusted using the opening cross-section
of the controllable control valve and as a function of the
temperature of the vaporized or overheated working medium after the
vaporizer.
[0028] The invention will be explained for exemplary purposes
hereafter on the basis of exemplary embodiments and the appended
figures.
[0029] In the figures:
[0030] FIG. 1 shows, in schematically simplified form, a design of
a steam circuit process device according to the invention.
[0031] FIG. 2 shows a further design of a steam circuit process
device according to the invention.
[0032] FIG. 1 shows, in schematically simplified form, the basic
components of a steam circuit process device. Liquid working medium
is pumped using a working medium pump 1 to the vaporizer 2 from a
reservoir 5. In the vaporizer 2, the vaporization of the working
medium occurs, the thermal energy required from this purpose being
supplied from a burner unit (not shown in detail). The steam
circuit process device is particularly preferably part of a vehicle
drive having an internal combustion engine, whose waste heat heats
the working medium in the vaporizer 2. In particular the exhaust
gases of an internal combustion engine come into consideration, the
components required for this purpose not being shown in detail in
FIG. 1 to simplify the illustration. The vaporizer 2 can be
constructed as multistage, in particular, a superheating unit can
be provided for the vapor phase.
[0033] The working medium is supplied in the vaporized state from
the vaporizer 2 to the expander 3 via a line 8, in which it
performs mechanical work while expanding. Following the expander 3,
the working medium is liquefied in the condenser 4 and returned
back into the reservoir 5.
[0034] The expander 3, which can generally also be referred to as a
steam-driven engine, is implemented, for example, as a piston
machine, steam turbine, or rotary machine.
[0035] An internal gear pump is used as the preferred working
medium pump 1, whose speed is adjusted independently of the volume
flow specification in the supply line to the vaporizer 2.
[0036] A bypass line 7 is provided in the area of the outlet side
of the working medium pump 1, which opens at one end in the
condenser 4 and thus mixes liquid working medium with the vaporized
working medium flowing from the expander 3 into the condenser 4.
The bypass line 7 comprises a valve 6, which can be implemented as
a controlled overflow valve or pressure limiting valve, for
example. It can also be a proportional valve which is actuated
electrically, electromagnetically, pneumatically, or mechanically
in this case. The valve 6 can be actuated by a central control
unit, such as an onboard computer, for example.
[0037] Suitable sensors for recording the pressure can also be
situated in the valve 6 and/or in the bypass line 7, which transmit
signals for the regulation or control to a central control
unit.
[0038] FIG. 2 shows a further exemplary embodiment of a steam
circuit process device according to the invention, the same
reference numerals as in FIG. 1 being used for corresponding
components. For the illustrated exemplary embodiment, the bypass
line 7 opens into a line 8 which connects expander 3 and condenser
4 to one another to conduct working medium. In the present case,
the bypass line 7 therefore opens directly into the line 8 leading
out of the expander 3, where the liquid phase from the bypass line
7 is mixed with the essentially vaporized phase of the working
medium (exhaust steam from the expander 3). The connection point
can be implemented as a T-shaped connection pipe, for example. A
nozzle, which atomizes the liquid working medium from the bypass
line 7, can be provided in the part of the connection pipe facing
toward the bypass line 7. The nozzle can also be situated in the
bypass line 7. An enlargement of the liquid surface of the liquid
working medium is to be performed by the nozzle, so that the
vaporized working medium leaving the expander 3 cools off more
rapidly when it hits the liquid droplets of the atomized working
medium. Atomization can be performed, for example, by suction or
supply of air, such as ambient air. Of course, it is also
conceivable to apply the liquid working medium from the bypass line
7 in the connection pipe and/or in the supply line by wetting on
the inner sides of the line 8 or the connection pipe.
[0039] Furthermore, manifold embodiments are conceivable, the basic
principle remaining the same: The working medium is branched off at
the exit of the working medium pump 1 or downstream from the
working medium pump 1, before or in the area of the vaporizer 2,
and supplied to the vaporized working medium of the expander 3 for
cooling.
LIST OF REFERENCE NUMERALS
[0040] 1 working medium pump [0041] 2 vaporizer [0042] 3 expander
[0043] 4 condenser [0044] 5 reservoir [0045] 6 valve [0046] 7
bypass line [0047] 8 line
* * * * *